import 'package:flutter/material.dart';
void main() => runApp(MyApp());

class MyApp extends StatelessWidget{
  // 重写方法
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Welcome to Flutter',
      home: Scaffold(
        appBar: AppBar(
          title: Text('Welcome to Flutter')
        ),
        body: Container(
          color: Colors.red,
          child: new Align(
            alignment: Alignment.centerRight,
            child: new ClipRRect(
              borderRadius: const BorderRadius.all(const Radius.circular(90.0)),
              child: Container(
                width: 180,
                height: 180,
                color: Colors.blue
              )
            )
          )
        )
      )
    );
  }
}